Abrading pad



K. H. BOWEN ABRADING PAD Aug. 6, 1935.

Filed Feb. 28, 1935 Patented Aug. 6, 1935 UNITED STATES PATENT OFFICE ABRADING PAD Application February 28, 1935, Serial No. 8,782

3 Claims.

This invention relates to improvements in fibrous abrading or bufling members and particularly to a carrier commonly referred to as a pad, adapted to have an abrasive material applied to one of its side surfaces.

Abrasive or bufling pads of fiber having an abrasive substance applied to one side surface, are used by pressing that side against the work.

I Usually, the major portion of the abrading or bufiing is done with the peripheral portion of said side and the thickness of the pad is generally such that the pad bends, setting up destructive internal stresses in the pad. The bending action takes place at the peripheral portion of the pad and, if localized, the fibers forming the flexed portion are placed under severe tensile strains which ultimately destroy the usefulness of the pad.

The primary object of this invention, there- 'fore, is to produce a fiber pad of this type which is capable of being distorted laterally without imposing destructive stresses on the fibers composing the same.

A further object is to produce a fiber abrading or bufiing pad in which the bending stresses will be distributed over a comparatively large area of the pad.

Another object is to construct an abrading or bufling pad of fibers with the latter so arranged periphery of the pad whereby circumferential elongation of the pad and the consequent imposition of localized stresses on the fibers by v bending, will be eliminated.

More specifically the present invention contemplates a fibrous abrading or buffing pad having its abrasive carrying surface or peripheral portion composed of elongated vegetable fibers arranged in a continuous length coiled or wound 'spiraliy with substantially all the fibers of said continuous length lying in substantial parallelism circumferentially of the pad and with one end portion of said length terminating at the periphery of the pad, said end portion forming an inextensible band around the periphery. By regulating the pressure and/or tension on the length of fibers as it is wound into the pad, the individual fibers are wedged between contiguousparallel fibers to the extent necessary to give the finished pad the desired density or compactness.

With these and other objects in view, the invention consists in certain details of construction and combinations and arrangements of that they will form an inextensible band at theparts, all as will hereinafterbe more fully described and the novel features thereof particularly pointed out in the appended claims.

In the accompanying drawing- Figure 1 illustrates more or less diagrammatically, in side elevation, apparatus for producing 5 the present pad;

Fig. 2 is a top plan view of the apparatus;

Fig. 3 is a perspective view of the pad, without the abrasive; and

Fig. 4 is a perspective view illustrating the action of the pad when lateral pressure is applied thereto as when in actual use.

Preferably, a long vegetable fiber, such as hemp, is used in making up the present pad. The fibers are first formed up into a continuous length, such as indicated at ill, with the fibers arranged in parallelism with one another longitudinally of said continuous length. This may be done by passing the fibers through the machine ordinarily used in rope and cordage factories for preparing fibers preliminary to the spinning of yarns.

The fibers, thus prepared, are wound on the pad form or spool consisting of side plates H and core member M In the form of spool illustrated, the plates I, one having the core I4 formed integrally therewith, are threaded on a shaft II. After the pad is wound, it may be readily removed by backing oil? the outer disk .ll. Shaft .II has mounted thereon a pulley I 8 to which power is applied by belt is from drive shaft 20.

The continuous length of fibers I0 is fed to the winding spool or form over a guide II and between spreader devices II. From spreaders I! it passes between rotating rolls I 3, It, yieldingly urged toward each other and driven at a constant peripheral speed. Before reaching the winding spool, a suitable binder such as latex cement or glue is applied. In the present instance, binder from a reservoir I 6 is sprayed on the fibers through nozzles l5 but other means may be employed. As the length of fibers is wound around the spool the successively formed convolutions are pressed radially inward by pressure roll 2! journaled in pivoted bearing members 22 yieldingly urged toward the spool by spring 23.

To properly tension the fibers and impart the desired density or compactness to the finished pad during the winding thereof. shaft I1 is made sectional and a friction or slip clutch interposed between said sections. Said clutch may consist of a plate 2 fast on one shaft section frictionally engaging a second plate 24" loose on the posed elements.

other section, but urged toward plate 24 by springs 25 interposed between said plate 24'- and a plate 28 test on said other shalt section. Springs 25 may be coiled around bolts 2i threaded. through plate 25 and loosely engaging plate 24, so that by adjusting nuts 26 on bolts 21, the frictional engagement between plates 20, 26, can be varied or regulated at will. Oi course, it desired, the tensioning of the length of fibers may be controlled manually.

One side surface of the pad is adapted to have applied thereto r. surface capable of performing the desired work, either bumng or abredlng. The application of the necessary material 'is s. matter of common knowledge in the art.

In pads of this construction, the fiber elements of each succeeding convolution embed or wedge themselves radially between iurteposed elements oi the some convolution and also oi the preceding convolution, leaving a substen= tially smooth peripheral suriece. This is especially true where the continuous length of material is composed of individual fibers, because of the comparatively small diameter of the fiber. In other words, elements oi small diameter are preferred as the larger the diameter, the larger will be the valley or depression between junta- In all forms it is due to the association of the elements in parallelism circumferentially of the pad and, by the same token, the absence of transversely disposed elements in the mass. These factors lend to the production oi a very compact pad construction. A further advantage is the presence of a minimum number of ends at the peripheral surface of the pad, thus eliminating, or at least reducing the dressing or finishing oil that surface before the application of the abrasive or other covering.

It will be appreciated that by careful manipue lation of the length of fiber material til, the side members it or the winding spool may be dispensed with but their use is, of course, preferred. It may also be desirable to place the pad, after being wound, and before the binder has dried, in a mold under pressure and permit it to dry thereinj This is not essential but, with certain types of binders the strength of the latter is increased. Where latex, in a vulcanizable compound, is used as a binder, heat should be applied to the mold, to vulcanize said binder. Again, it will be appreciated that the density or resiliency of the pad may be varied by the amount of animal glue used in the binder. It will also be appreciated that a core of greater diameter than that shown may be used, it only being necessary that the peripheral body portion of fibrous construction be of sumcient depth radially of the pad to perform the desired work. As illus- .trated, the pad is comparatively thin and, as will be understood,. when the side of the peripheral portion of the pad is forced against work, the

, pad flexes laterally.

In addition to the disposition of the individual fibers in parallelism; to one another, continuous length of fibers results in the formation of sub-.

stantially inextensible bands of fibers. This is because when any given portion of the pad is so flexed, this band formation distributes the stresses circumlerentially oi the pad instead of permitting such strains to be localized at the point oi flexing. Such action is clearly shown in Fig. e, where the application of lateral pressure in one direction is indicated by the arrow and in which illustration the peripheral portions 30 of thepad are shown flexed in the opposite direction. From this, it is clear that the flexing stresses at the periphery of the pad have been transmitted by the ineirtensible band-like fibers to the points 3b.

The expression "uniabricated fiber elements is used herein as defining a number of elements each composed of an individual fiber or a plurality of such fibers, the elements themselves as a group being uniabrlcated in that they are not interwoven.

Whet I claim is:

,l. A pad. body of disk-like formation adapted to have an abrading substance applied to one side surface thereof and adapted to hex under lateral pressures imposed on the peripheral portion thereof, said body adjacent the periphery thereof being formed of a. continuous length of unfabricated fiber elements wound in successive convolutions with one end of said length of fiber elements terminating at the periphery of the pad, said elements being arranged in parallelism with one another circumferentially of the pad, the elements at said periphery constituting a substantially inextensible band capable of distributing flexing strains circumferentially of the pad, and a binder v for bondingsaid fiber elements together.

2. A pad body of disk-like formation adapted to have an abrading substance applied to one side thereof and adapted to flex under lateral pressures imposed upon the peripheral portion thereoiflthe peripheral portion of said pad being formed of a continuous length of elongated vegetable fibers arranged in superposed convolutions with substantially all the fibers in said length arranged in substantial parallelism circumferentially of the pad, each individual fiber being wedged radially between fibers contiguous thereto, and one end portion of said continuous length of fibers forming a substantially inextensible band around the periphery of said pad capable of distributing flexing strains circumferentlally of the pad, and a binder for bonding said fibers together.

3. A pad body of disk-like formation adapted to have an abrading substance applied to oneside surface thereof, and adapted to fiex under lateral pressures imposed on the peripheral portion thereof, said body adjacent the periphery thereof being formed of a. continuous length of fiber elements, substantially all of said elements being disposed in substantial parallelism longitudinally of said length, and said continuous length of elements being wound in successive convolutions into said body with one end of said length terminating at the periphery of said pad, the elements at the periphery of the pad constituting a substantially inextensible band'capable of distributing flexing strains circumferentially of the pad, and a binder for bonding said elements together. 1

V KENNETH H. BOWEN. 

